Hi Jason, I am using the Adobe Nav app on my iPad in conjunction with a 27" imac. Here's what I like about it: seamless integration with Photoshop CC, nice size tool icons, and whether I am using a mouse or a Wacom Intuous 5 to navigate the image, I am finding it faster to use than most keyboard shortcuts. here is my current workign set up. The iPad is in a Wallee shell which it turn is connected to the manfrotto Magic Arm via a Tethertools Wallee Connect.
I also use the Connect+Wallee combination in various ways (generally CamRanger is involved as well) when shooting.
Adobe Nav app: http://www.photoshop.com/products/mobile/nav
Wallee and Tethertools Connect: http://www.tethertools.com/plugging-in/wallee-ipad-modular-case/
Full disclosure: I have no business, financial or professional connections with any of the above companies.